Personalized medicine slowly taking shape

By Ben Hirschler

NEW YORK (Reuters) - Personalized medicine -- tailoring treatments to an individual's genetic profile -- has been one of the main dreams of the gene revolution, but putting it into practice is proving tough.

While advances are being made in a few areas, so-called pharmacogenetics will not change the commercial landscape for the bulk of pharmaceuticals for several years, drugmakers told the Reuters Health Summit in New York this week.

"Pharmacogenetics is not going to transform this market any time soon," said Jean-Pierre Garnier, chief executive of GlaxoSmithKline Plc.

"Let's be clear -- it's going to take 20 years plus. Does that mean you are going to have zero happening? No. It's already happening. But it is going to be very specific examples."

The decoding of the human genome in 2000 sparked hopes that a new era of tailored medicine was just around the corner.

In fact, uncovering the genetic differences that determine how a person responds to a drug, and developing tests, or biomarkers, for those differences, is proving more challenging than initially hoped.

As a result, people with complex diseases like depression are still being prescribed medicines on a trial-and-error basis, and adverse drug reactions remain a major cause of injury and hospitalizations.

That is not stopping companies from investing in the field.

One pioneer is Roche Holding AG, which already relies on genetic tests to determine if women with breast cancer will respond to its drug Herceptin. Roche has offered $3 billion to acquire Ventana Medical Systems Inc to build its presence in this area.

Glaxo, too, has work in progress, with a large clinical trial now under way to see if an extended-release version of diabetes drug Avandia -- recently tainted by safety worries -- can help a sub-set of people with Alzheimer's disease.

SHOTGUN TREATMENT

Pharmacy benefit manager Medco Health Solutions Inc CEO David Snow believes genetic profiling will be key to future patient care, as well as costs.

"Right now, medicine is practiced in a shotgun way. It is very inefficient and very wasteful," he said.

Medco is starting to address the issue product by product, starting with Bristol-Myers Squibb Co's Coumadin, also known generically as warfarin, a notoriously difficult to use blood thinner that can cause serious bleeding in some patients.

The Food and Drug Administration announced in August that Coumadin would come with new instructions explaining that people with certain genes may need a lower dose.